1. Field of Invention
The present invention relates to a fan and its impeller and housing, and in particular, to a fan and its impeller and housing with enhanced structural strength.
2. Related Art
As shown in FIG. 1, a conventional fan housing 1, severing as a base of a fan, includes a base portion 11 and a sidewall portion 12. The sidewall portion 12 is perpendicularly disposed around and connected to the base portion 11.
Generally, the fan housing 1 is made by injection molding. As shown in FIGS. 2 and 2A, the thickness D1 of the base portion 11, the thickness D2 of the sidewall portion 12, and the thickness D3 of the connection between the base portion 11 and the sidewall portion 12 are not the same. As the results, there are defects, such as protrusions and bubbles, which are easily formed at the connection due to non-uniform thickness. Further, non-uniform thickness will cause deformation of the whole shape.
In order to keep the thicknesses D1, D2 and D3 to be uniform and prevent from the shape deformation after injection molding, a conventional solving method is forming, an arc (as shown in FIG. 3) or a groove (not shown) at the connection between the base portion 11 and the sidewall portion 12. However, that weakens the structural strength of the fan housing 1.
Except for the fan housing 1, the impeller of the fan can be also made by injection molding. The same disadvantages, such as the defects and shape deformation, exist caused by injection molding during manufacturing processes.
It is thus imperative to provide a fan and its impeller and housing to solve the above-mentioned problems.